1. Field of the Invention
The present invention relates to a developing cartridge and an electrophotographic image forming apparatus employing the same. More particularly, the present invention relates to a developing cartridge which includes a photosensitive drum and a developing roller, and an electrophotographic image forming apparatus employing the developing cartridge.
2. Description of the Related Art
An electrophotographic image forming apparatus emits light onto a photosensitive medium that is electrostatically charged with a uniform potential and forms an electrostatic latent image corresponding to a desired image. Then, the electrophotographic image forming apparatus supplies toner to the electrostatic latent image to develop the image, transfers the image onto an intermediate transfer medium or directly onto a print medium, and then applies heat and pressure to the transferred image to fix the image thereon to print the image.
An electrophotographic image forming apparatus includes a developing cartridge. The developing cartridge includes a photosensitive drum and a developing roller. In a non-contact developing method employing a developing cartridge, the developing roller is spaced from the photosensitive drum to form a developing gap. The developing gap is a very important factor to take into consideration for printing good quality images and producing high developing efficiency. The developing gap preferably is maintained constant during the printing operation. The photosensitive drum and the developing roller rotate via connection to power transmitting elements such as a motor, a gear, or a belt. Vibrations produced while the photosensitive drum and the developing roller rotate, change the developing gap. Thus, vibrations may deteriorate the quality of a printed image.
Accordingly, there is a need for a developing cartridge which can maintain a constant developing gap and reduce vibrations.